Nextcloud: Unauthorized force-mute from missing permission check when using internal signaling

published 2026-06-01 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-33678

cvss: 3.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits: 0; none known

Nextcloud is an open source content collaboration platform. Prior to versions 21.1.10, 22.0.11, and 23.0.3, a low-privileged user can force other user's microphones to be muted in calls when no High-performance Backend is installed. This issue has been patched in versions 21.1.10, 22.0.11, and 23.0.3.

Patch / fix

fixed in 1 links 1

nextcloud spreed 21.1.10, 22.0.11, 23.0.3

github.com/nextcloud/spreed#17577 pull request

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-06-01)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	3.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Affected products

nextcloud security-advisories

Classification

Weakness

CWE-284 Improper Access Control

References

Sources

CVE List CVE-2026-45266
NVD CVE-2026-45266

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary